Feeding mechanism



oct. 21, 1941',

J. STUART, ZID

l FEEDING MECHANISM Filed Sept. 28, 1939 JOSEPH STUART n I INVENToR CW 65. AM

ATTORNEY Patented Oct. 21, 1941 FEEDING MECHANISM Joseph Stuart, II, Wilmington, D el., assgnor to Hercules Powder Company, Wilmington, Del., a corporation of Delaware vApplication September 28, 1939, Serial No. 296,962

4 Claims.

Thisinventionrelates to va feeding mechanism and .more .particularly to a mechanism for feedingstrands or filaments of 'relativelysmall diam- ;eter at a definite rate and under controlled tension.

The manufacturer of devices such Aas electric firingdeviceaelectric bulbs, radio tubes, etc., are .faced with ther problem of feeding filaments of relatively small diameter .to the various operations. These filaments are not sufficiently stiff to ,prevent curl-ing and are therefore very difficult to handle. Many attempts have been made to provide a simple and effective means for .feeding the necessary sections of filaments to the devices being `manufactured but these have not been` entirely successful in obtaining a mechanical device which will operate efficiently. Thus, for example, in the manufacture vof blasting caps, `the electric firing devices contain a high resistance element which is vnormally composed of avery fine platinum alloy wire. This -wire element which is normally between 4'0.001 and 0.002 inch in diameter is obtained from a spool of wireand the `lengths have a decided tendency. to curl tightly upon itself. The wire is, ofcourse, very fragile due .to its relatively .small diameter and this with its curling characteristic makes various operations with it extremely :difficult. At .present the element is normally solderedfgor welded to the proper terminals by highly sllnlledlabor,V :and this :process is very tedious, slow and exacting on the operators.

The present invention aims to provide a suitable mechanism for feeding the filaments of rela- .tively Vsmall diameter to the various types of operations at the correct speed and4 under the desired tension. The provision of such a feeding. devicewill lill a long needed want in various-industries'.

Theo'bject .of the present invention is therefore to provide a mechanical means of delivering a strand or filament Yto any .desired operation,

A further object of this invention is to prov-ide a Amechanical means 'of feeding -a strand fby which a section of the strand supported at each lend is presented -to `an operation.

YA further `object of this invention-is torprovide a means of :feeding a high resista-nce wire of relative small diameter toa soldering or welding .unit of, for example, an electric firing device assembly machine.

. A vstill further object of this invention is to provide a mechanism which will prevent 'waste of .the zlaments being 1356.61.

A still further oblectzof :this invention is to vide Va mechanism which presents section of a filament under the desired tension to an operation.

Other vand further objects of this invention will be obvious upon an understanding of the illustrative embodiment about to be described .or will be indicated in the appended claims.

A preferred embodiment of this invention has been chosen for purpose of illustration and description .and is shown in the, accompanying drawing, rforming part of the specification wherein,

Figure 1 is aside .elevation of the feeding mechanism.

Figure 2 is a partial cross-sectional View taken along line 2-.2 on Figure l and .shows the spider leg clamping means in theposition of picking up a Wire; and

Figure 3.is a partial cross-sectional view taken along line 3-.3 on Figure 1 and shows a device for cleaning scraps of wire from the clamping means :or .spider legs.

...Described generally, the machine embodying the present invention .for feeding filaments or strands of relatively small diameter comprises means for guiding the strand to a rotatable pick-up means such as a Apiclr-up spider which has :a series of clamping means designed to receive and engage the strand. There is suitable means such as a cam located `in proper relation to the Astrand guide and rotatable pick-up to effect the vopening yof the clamping means and cause them to receive and engage the strand. The strand is thus fed through the guide to the rotatable means and engaged at successive points thereby presenting -a series of .supported sections of the strand to any specic operation such as -a welding unit or the like. At the operation, the supported section of wire is used and then severed 'in a suitable manner at the proper points. A device vsuch as a knife edge Wedge is located at a point just after the welding .or similaroperation and cleans any scrap of filament from between the clamping means if such scrap remains therein.' The clamping .means then returns to vthe .guide and again clamps the filament.

Referring again to vthe drawing, there is shown a machine in which va 'strand or filament l of relatively small diameter enters the feeding mechanism which includes a support bar 2 upon which is mounted a strand guide 3 comprising a member .4 attached to the support bar 2 and .uponvvhich is positioned members 5 and 6 in a manner so as to forma narrow directing channel r1 through which the` strand l 'is led toa pick-Yup spider 8. The members of the strand guide 3 are fastened into position by suitable means such as screws or bolts shown as 3A.

The strand I entering the guide 3 may be obtained from a spool or similar reserve, not shown, which may be, if desired, mounted on the support bar 2 at any convenient point. I have found it desirable to mount the spool with a braking or drag device attached thereto so that it may keep the strand under a very slight tension. This braking action or drag prevents free running of the spool and backlashing of the strand and allows the strand to be kept under Acontrolled tension throughout the feeding operation.

The strand I leaving the channel I is picked up by the spider 8 which preferably comprises to produce neat operations. This severing oper'- ation may leave scraps of wire between the pins and spring.

After the welding or similar operation, there thus is usually a small scrap of the strand I5 remaining between the pin and the spring leaf. In order to remove this scrap of the strand I5 a scrap ejector I6 is mounted on the support bar 2 and comprises a knife edge Wedge I'I which is shaped and positioned to enter between the spring leaf I0 and the pin II and remove the 'scrap I5, Figure 3. The wedge is attached to a rigid support I8, by means I9 which support a rotatable substantially non-yielding spider disc j it will be noted that the spring leaf I0 is of double construction, while I have found this method of construction preferable, I mayalso use a single leaf construction or a multiple leaf construction depending only upon the use and dimensions of the spring leaf. l

In these figures it will also be noted thatV I have indicated that pins II are inserted in thev end of each spider leg for the spring'leaf tobear upon, but it is to be understood that I may use a boss or projection of any suitable type-in place of a pin. The boss or projection may, if desired, be cast on the spider legs. i

The operation of opening the spring leaf I9 from the pins II is accomplished by a-xed cam I2 which may be integral with members 5 and 6 of the guide. The spring leaf IIl is shown only partially cross-hatched and indicated by a ghost line for clarity in Figure 12. The cam I2 actsin a mannerY to move spring leaf III away .from the spider disc S and the pin II, and so allows the strand Iv to be led between the pin and spring leaf between which it is tightly clamped when the spring leaf is released when the end of the cam I2 is reached.. The further rotation of the spider draws the wire out from the guide and r brings another leg of the spider into position to clamp the wire. Thus, is provided a section of wire supported at both ends and under controlled tension.

The strand is therefore clamped between the pin projecting from the rigid spider disc and the spring leaf at regular intervals and'carried in this manner under controlled tension toa station I3 for use. 'I'he station I3 may be, for example,

a welding device that uses the section of strand,

which may be a ne wire, for bridging the tW terminals I4.

Itis to be understood that I contemplate either moving thev feeding mechanism'toV the` welding station I3 or the welding station to the feeding mechanism whichever is more convenient. Further, that I have indicated. the wire being fed to a welding station only by way of illustration and that I may feed the wire in a similar manner to any desired operation such as, for example, a soldering station, a station for transferring lthe wire to other operations or. similar operations that require newire under` icontrolled tension. Further, I may, if desired, cut the wire after welding it to the terminal or in otherwayssever it is fastened to the main support bar 2.

The spring leaf I0 is held in the desired resilient compressive relation against the pins II o f the disc by a washer 20 and adjusting means 2|. The adjusting means 2| shown may be designed to individually control the tension of each clamping means if so desired.

The yrelative position of the strand guide and scrap ejector with reference to the circumference of the spider is shown in Figure 1 to be approximately diametrically opposite each other. This is not essential but is only so shown for clarity. It is, therefore, to be understood that I contemplate positioning the guideV and ejector at the most desirable points forrperforming their functions while the strand is delivered to the specific operation desired. The scrap ejector may, if desired, be combined with the spreading cam but I prefer to use a separate station-to perform this operation.

.It will be obvious to those skilled in the art that I may motivate the shaft upon which the rotatable spider is mounted in many ways Vsuch as by a motor, by gears', ratchet, or manually. I prefer to drive the shaft .by ratchet means as in this manner' the speed and length of movement are easily controlled.

' It is. to be understood that wherein this specification and claims I refer to strand or filaments I include strands and filaments having irregular cross-sections, for example, rectangular, polyhedral or ribbon like as Well as the normal strands and laments having a substantially circular cross-section.

It will be seen that the present invention provides a simple efficient machine for feeding strands of relatively small diameter to any particular operation and particularly for feeding high resistantwire of the type used in electric blasting caps to a welding station. The machine is very simple but effectively feeds those strands which are fragile and tend to curl tightly upon themselves.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to' be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense. I

What I claim and desire to protect by Letters Patent is:

1. In a device for feeding a strand having relatively small diameter, the combination of means for guiding a strand, a rotatable spider adjacent said guiding means comprising a series of substantially radially extending legs vand a clamping member on each of said legs and adapted to engage the strand and hold it against kand adjacent the end of said legs, andmeans for operating saidclamping members to cause Athem to receive and engage the strand.

2. In a device for feeding a strand having -a relatively small diameter, the combination of means for guiding a strand, rotatable means adjacent said guiding means comprising a substantially non-yielding spider having legs provided With a projection adjacent the ends thereof and a spring member on each leg bearing upon the projection, and a cam for moving the spring members away from the projections to receive and then engage the strand.

3. In a device for feeding a strand having a relatively small diameter, the combination of means for guiding the strand, a rotatable spider adjacent said guiding means, having a series of substantially radially projecting members, a resilient clamping member on each of said projecting members normally engaging said projecting members adjacent the ends thereof and adapted to engage portions of the strand and clamp it against said ends of said projecting members, and means for operating said clamping members to cause them to receive and engage the strand.

4. In a device for feeding a strand having a relatively small diameter, the combination of means for guiding a strand, rotatable means adjacent said guiding means comprising a substantially non-yielding spider having legs provided with a projection adjacent the ends thereof and a spring member on each leg bearing upon the projection, and a cam for moving the spring members away from the rprojections and receive and then engage the strand and means for removing scraps of the strand from between said projection and spring member.

JOSEPH STUART, II. 

